Circulating device for loose materials, especially aerobic decomposing organic waste materials

ABSTRACT

A circulating device for loose materials, especially for aerobic decomposing organic waste materials comprising a freely suspended, revolving, endless heavy link or jointed mat or conveyor structure which is guided over two upper deflecting devices arranged in spaced relationship from one another at an undercarriage, at least one of such deflecting devices being driven. The link mat is equipped at its outside surface or face with entrainment devices for the loose material, such entrainment devices being divided over its surface. The direction of rotation or revolving of the link mat occurring from the top towards the bottom at the side situated in the direction of advance of the circulation device.

United States Patent 1 Feb. 15, 1927 Gujer [541 CIRCULATING DEVICE FORLOOSE MATERIALS, ESPECIALLY AEROBIC DECOMPOSING ORGANIC WASTE MATERIALS[72] Inventor: Hans Gujer, Glattalstrasse 149, Rumlang Zurich,Switzerland [22] Filed: May 27, 1970 [21] App]. No.: 40,962

[30] Foreign Application Priority Data May 28, 1969 Switzerland 8089/69[52] US. Cl ..259/ 183 [51] Int. Cl. ..B01f 7/00 58 Field of Search..259/182, 183, 184, 99, 1 R,

259/2; 172/100; 37/191R, 191 A, 192 R, 192 A [56] References CitedUNITED STATES PATENTS 1,622,280 3/1927 Fasting ..259/l84X 1,092,0863/1914 Wilson 1 72/100 FOREIGN PATENTS OR APPLICATIONS 325,105 7/1918Germany ..l72/100 Primary Examiner-Walter A. Scheel AssistantExaminerPhilip R. Coe AttorneyWerner W. Kleeman ABSTRACT A circulatingdevice for loose materials, especially for aerobic decomposing organicwaste materials comprising a freely suspended, revolving, endless heavylink or jointed mat or conveyor structure which is guided over two upperdeflecting devices arranged in spaced relationship from one another atan undercarriage, at least one of such deflecting devices being driven.The link mat is equipped at its outside surface or face with entrainmentdevices for the loose material, such entrainment devices being dividedover its surface. The direction of rotation or revolving of the link matoccurring from the top towards the bottom at the side situated in thedirection of advance of the circulation device.

21 Claims, 9 Drawing Figures CIRCULATING DEVICE FOR LOOSE MATERIALS,ESPECIALLY AEROBIC DECOMPOSING ORGANIC WASTE MATERIALS BACKGROUND OF THEINVENTION The present invention relates to an improved circulationdevice for loose materials, especially for aerobic decomposing organicwaste materials.

There are already known to the art a whole series of circulating devicesfor the mixing or circulation of loose materials, especially also forthe periodic circulation of organic waste materials during their aerobicdecomposition.

A known apparatus for this purposes uses vertically arranged feed wormswhich upwardly convey the material in vertical direction and then ejectsuch opposite to the direction of advance of the circulation apparatus.Furthermore, an additional prior art circulation device is knownemploying a revolving endlessconveyor band which is suspended between anupper and a lower deflecting device. The conveyor band is equipped withprongs or teeth which scrape away the material to be circulated in avertical direction from the bottom towards the top of a heap of loosematerial and rearwardly eject such material opposite to the direction ofadvance of the circulation device. What is common to these prior artcircula tion devices is that they all possess a relatively complicatedconstruction. Additionally, they require not only a drive mechanism forthe feed worms or the revolving conveyor band, respectively, butfurthermore need a drive mechanism for the forward movement of thecirculation device. Therefore, the known physical manifestations ofprior art circulation devices of this type are relatively expensive.

SUMMARY OF THE INVENTION Accordingly, there is a real need in the artfor an improved circulation device for loose materials which is notassociated with the aforementioned drawbacks of the prior artconstructions. It is a primary object of the present invention toprovide just such an improved circulation device which fulfills thisneed quite capably.

Another, more specific object of the present invention relates to animproved circulation device for the agitation or mixing of loosematerials, especially aerobic decomposing waste matter, which possessesan extremely simple construction, can be produced economically, and yetstill possesses great effectiveness and operational reliability.

Now, in order to implement these and still further objects of thepresent invention, which will become more readily apparent as thedescription proceeds, the inventive circulation device for loosematerials, especially aerobic decomposing organic waste materials, isgenerally manifested by the features that it comprises a freelysuspended, revolving, endless, heavy link or jointed mat which is guidedover two upper deflecting devices arranged at a spacing from one anotherat an undercarriage or wheel frame. At least one of these deflectingdevices is driven. Furthermore, the link mat is equipped at its outerside with entrainment devices for the loose material which aredistributed over its surface andthe direction of revolving of the linkmat occurs from the top towards the bottom at the side thereof situatedin the direction of feed or advance of the circulating device.

The inventive circulating device manifests itself by virtue of itsexceptionally simple construction since for the freely suspended,revolving, endless link mat there is only required two upper deflectingdevices arranged at a spacing from one another upon a travellingundercarriage or the like. By virtue of the freely suspended or hangingarrangement of the link mat the use of lower deflecting devices becomessuperfluous. This brings about a noteworthy simplification of the entireconstruction of the unit, and moreover, it is possible to dispense withjust that or those deflecting devices which otherwise would be situatedat the region of the loose material to be circulated. In that case, suchdeflecting device would be subject to contamination or soiling by theloose material and would be in danger of becoming damaged.

The immersion or introduction of the link mat into the loose material isensured in that the link mat is constructed to be quite heavy and,therefore, during the circulating or revolving operation cannot climb orascend. If desired, it is possible to provide an additional weightingmechanism at the lower turning or deflecting region of the link mat atits inner side. In that event such weighting mechanism can likewisepossess an extremely simple construction. For instance, it is possibleto use as the weighting mechanism a simply freely bearing rolle body.

Due to the freely suspended arrangement of the link mat at two upperdeflecting devices arranged in spaced relationship from one another atan undercarriage or wheel frame, the direction of movement or orbit ofthe link mat approximates that of an inverted isosceles triangle.Furthermore, since the direction of revolving of the link-mat takesplace from the top towards the bottom at the side thereof disposed inthe direction of feed of the circulating device, the circulating devicetends to automatically embed itself or eat into the loose material.Consequently, it is unnecessary to provide an additional drive mechanismfor the circulating device for its further movement. On the other hand,it can be advantageous to equip the circulating device with a brakemechanism controlling its feed motion, so that, if necessary, a climbingof the link mat upon. the loose material can be prevented.

The circulating device of the present invention is especially suitablefor the periodic circulation or mixing of organic waste materials duringtheir aerobic decomposition, for instance has been described in maycopending U.S. application, Ser. No. 780,829 now U.S. Pat. No. 3,553,844filed Dec. 3, I968 and entitled Method and Means for Continuously DryingWet Organic Waste Matter, Particularly Fresh Sludge, Through AerobicPrecompositing. In so doing, the circulating device is placed upon theupper edge of an elongate or circular ringshaped container and immersesinto the loose material to be circulated with its freely suspended,revolving, endless heavy link mat.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood and objects other than those set forth above will becomeapparent when consideration is given to the following detaileddescription thereof. Such description'makes reference to the annexeddrawings wherein:

FIG. 1 is a schematic cross-sectional view of a preferred embodiment ofinventive circulating device shown in its operable position;

FIG. 2 is a fragmentary front view of an enlarged scale of the link matused in the circulating device of FIG. 1;

FIG. 3 is a sectional view of the link mat depicted in FIG. 2, takensubstantially along the line III-III thereof;

FIG. 4 is a fragmentary enlarged sectional view of a portion of the linkmat depicted in FIG. 2, taken substantially along the line IV-IVthereof;

FIG. 5 is a sectional view of the portion of the link mat shown in FIG.4, taken substantially along the line V-V thereof;

FIG. 6 is a side view of the circulation device depicted in FIG. 1;

FIG. 7 is a top plan view of the circulation device shown in FIGS. 1 and6;

FIG. 8 is a front fragmentary view of a link chain for a modified formof link mat and employing inclined disposed DETAILED DESCRIPTION OF THEPREFERRED EMBODIMENTS Describing now the drawings, the exemplaryembodiment of circulating device designed according to the teachings ofthe present invention and depicted in FIG. 1 comprises a so-called Thelink mat I is designed to be so heavy that when it revolves it tends todig into the loose material 6 without having the tendency to climb orsnake upwards. Furthermore, this link mat is equipped at its outer sidewith suitable entrainment devices 7 distributed over its surface. Theseentrainment devices 7, depending upon the intended use of thecirculating device, can be differently constructed. It is particularlyadvantageous to use as the entrainment devices 7 prongs or teeth 7awhich, once again, can have different configurations. When using thecirculating device for the periodic circulation or mixing of organicwaste matter during its aerobic decomposition it has been found to beparticularly advantageous to construct these entrainment prongs or teeth7a so as to be inclined opposite to the direction of revolving or travelof the link mat l, as generally indicated by reference character A inFIG. 1. Consequently, there is not only ensured for a gooddisintegration of the forwardly situated pile of loose material, butmoreover an automatic cleaning of the prongs or teeth 7a.

As already mentioned briefly above, and best seen by referring to FIG.1, the direction of revolving or travel of the link mat 1 occurs in thedirection of the arrow A, that is to say the link mat moves at its sidesituated in the direction of advance or feed B of the circulating devicefrom the top towards the bottom. Due to this construction it is ensuredthat the circulating device during its revolving movement of the linkmat 1 automatically digs into the pile ofloose material 6. An additionaldrive mechanism for the forward movement of the circulating device istherefore not necessary. In the exemplary embodiment depicted in FIG. 1the undercarriage or wheel frame 2 equipped with the travelling wheels 8of the circulating device is mounted at the upper marginal portion oredge 9 of a container 10 housing the loose material 6.

As best observed by referring to FIGS. 2-7, the link mat preferably iscomposed of individual juxtapositioned endless chain members 11, withthe links 12 of neighboring chains being articulated to one anotherthrough the agency ofa suitable coupling mechanism 13. The individuallinks 12 of the link chains 11 support the entrainment devices ormembers 7, which in the present embodiment have been constructed asprongs or teeth 7a, as particularly recognized by referring to FIG. 2.The inclination of these teeth or prongs 7a is best observed byreferring to the sectional view of the link mat depicted in FIG. 3. Therakelike link elements 12as viewed in their direction ofrevolving-starting from their center are inclined towards the rear atboth sides, so that they improve the circulation or mixing of the bulkor loose material.

The mutual coupling of the individual chains 11 forming the link mat orchain arrangement 1 is undertaken by means of the coupling devices 13more definitively shown with regard to FIGS. 4 and 5. These couplingdevices or mechanisms 13 possess an elongate or substantiallyhorseshoe-shaped eyelet 14. The links 12 of the chains 11 are equippedat their outer sides with bolt members or the like which piercinglyextend through the elongate eyelet 14 of the associated coupling device13. This type of coupling mechanism renders it possible to have thechains 11, in each instance, possess sufficiently great play so thatthey can laterally deviate somewhat towards one another.

As particularly apparent by referring to FIGS. 6 and 7, each chain 11 isguided per se over two upper deflecting devices 3 and 4. One of thedeflecting devices, such as member 3 of both deflecting devices 3 and 4,is driven by a suitable drive mechanism 16.

As particularly evident by referring to FIG. 7, it is ad vantageous toadjustably arrange the deflecting devices of the individual deflectingmechanisms 3 and 4 forming the link mat I, so that the planes ofrevolving for the individual chains 11 can be adjusted independently ofone another. In the exemplary embodiment of inventive circulating deviceas shown in FIG. 7 each chain 1 1 is not adjustable in its plane ofrevolution with respect to the other, rather, here in each instance twochains 11 are assembled together into an adjustable chain pair. To carryout convenient adjustment of the planes of revolution of the neighboringchain pairs it will be seen that the deflecting devices 3 and 4associated with each pair of chains 1 l are carried by a suitablesupport frame 40 which. in turn, is displaceably mounted at the movableundercarriage 0: wheel frame 2. For instance, the undercarriage or wheelframe 2 can be provided at the supporting struts or girders 2a withsuitably configured, such as arcuate shaped elongate holes which are notparticularly shown in the drawings, and with which movably engage theindividual support frames 40 so that such can be selectively shifted inthese elongate holes to thereby conveniently vary the relativedisposition of the respective planes of revolution of the individualchains 11 with respect to one another as explained above. The samearrangement could be obviously also provided for the adjustment of eachsingle chain 11. By virtue of the adjustment possibility of therevolving planes of the chains it is possible to regulate the dischargedirection of the individual chains or chain pairs with respect to theother chains or chain pairs. This is particularly then of importancewhen the circulating device is arranged upon a circular ring-shapedcontainer or the like and then is aligned at an inclination to the radiiof the container such that in addition tothe purely circulatory movementof the loose material such experiences an additional conveying movementfrom one side of the container to the other. By virtue of the additionaladjustability of the revolving planes of the individual chains it istherefore possible to regulate in an extremely fine or precise mannerthe feed movement of the loose material from one side of the containerto the other and to accommodate the circulating device to themomentarily required circulating conditions. Thus, for instance, it ispossible during the circulating of organic waste materials to bringabout a more intense feeding of the material, depending upon the degreeof the decomposition process. If the circulating device then is operatedin conjunction with a return feed device, this construction enablesobtaining a very individual circulation of the material to be treated.

Depending upon the type of material to be circulated or agitated it canoccur that the circulating device becomes accelerated due to therevolving of the link mat l to such an extent that the link mat climbsup upon the material to be treated and moves over such in the manner ofa roller mat. If that should occur, the circulation or agitation effectof the circulating device is suppressed and this device more readilyfunctions as a compacting mechanism for the loose material. In order toprevent this from occurring, it is advantageous to equip the circulatingdevice with a braking mechanism in order to control the feed oradvancing movement. To this end, it is possible to equip one of therevolving or travelling wheels 8 of the undercarriage 2 with a brakewhich can be more or less strongly adjusted depending upon therequirements. However, it is advantageous to equip the circulatingdevice with an additional friction wheel 17, acting as a brake, whichbears upon the travelling surface or container rim 9 and which iscoupled via a transmission 18 with the driven deflecting device 3. Owingto the action of the transmission 18 the fr iction wheel 17 can bedriven at a lower rotational speed than the deflecting devices 3 for thedriven chains 11, so that the friction wheel 17 which frictionally bearsupon the upper container rim 9 exerts a braking force upon thecirculating device. By virtue of this measure, it is ensured that thefraction wheel 17 automatically adjusts itself to the driven velocity orspeed of the link or articulated mat I and, therefore, the feed velocityor speed of the circulating device is accommodated to the revolvingvelocity of the link mat 1. It is here mentioned that in the exemplaryembodiment the deflecting members 3 and 4 are shown as rollers.

A further measure to prevent climbing of the link mat I resides inproviding at the inside of the link mat 1 at the lower deflecting regionS a suitable weighting mechanism. This weighting mechanism can be ofextremely simple construction FIGS. 8 and 9 depict a further exemplaryembodiment of links 12a for the chain 11 of the link or chain mat. Theselikewise rakelike constructed links 12a are arranged at an inclinationwith respect to the direction of revolution A of the mat. The inclinedposition of the links 12a is chosen such that-viewed in the direction ofrevolution-these links extend at an inclination to rearwardly to thatside in which there is intended a transverse transport of the loosematerial to be circulated.

As best shown by referring to FIG. 9, the mode of operation of such typeconstructed link mat is as follows: During the downward movement of thelinks 12a the entrainment prongs or teeth 7, viewed in the direction ofadvance B of the circulating device, scratch away material from the toptowards the bottom from the forwardly disposed compacted heap ofmaterial 6a. The loosened material falls downwardly between the teeth orprongs. A transverse feed or transport of this material does not yetoccur. At the rear side of the circulating device the links 12a movefrom the bottom towards the top. The prongs immerse into the loosecontinuously following rolling material 6b and continuously entrain thisloose material upwards, whereby parts of the material laterally roll offof the inclined positioned links 12a. Hence, in addition to acirculatory movement there is also achieved a transverse transport orfeed of this material.

The inclined position of the links 12a can either for themselves bringabout the transverse transport of the material or can serve to assist orsupport the transverse feed or transport of the material brought aboutby the inclined position of the entire circulating device as previouslyexplained.

While there is shown and described present preferred embodiments of theinvention, it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied and practicedwithin the scope of the following claims.

What is claimed is:

l. A circulating device for loose materials, especially foraerobic-decomposing organic waste materials, comprising an undercarriagemovable in a predetermined direction of advance, two upper deflectingdevices mounted in spaced relationship at said movable undercarriage, afreely suspended, revolving, endless heavy link mat structure guidedover said two upper deflecting devices, means for driving at least oneof said deflecting devices, entrainment means for the loose materialprovided at the outside surface of said link mat structure, saidentrainment means being distributed over said surface of said link matstructure, the direction of revolving of said endless link' matoccurring from its top towards the bottom at the side situated in thedirection of advance of the circulation device, said link mat structurebeing composed of individual adjacently arranged endless chains formedof link elements, and coupling means for hingedly connecting togethersaid link elements of neighboring chains.

2. A circulating device for loose materials as defined in claim 1,wherein said coupling means couples together neighboring link elementswith play.

3. A circulating device as defined in claim 2, wherein said two upperdeflecting devices comprises individual deflecting elements for eachrevolving chain moving through a respective associated revolving planewhich are adjustably mounted so that it is possible to regulateindependently of one another the said revolving planes of the individualchains.

4. A circulating device for loose materials as defined in claim 1,wherein said entrainment means comprise prong members arranged at saidindividual link elements.

5. A circulating device for loose materials as defined in claim 4,wherein said prong members are inclined opposite to the direction ofrevolving of said link mat structure.

6. A circulating device as defined in claim 4, wherein said linkelements are constructed to possess the configuration of substantiallyrakelike members which from their centerline are inclined rearwardly toboth sides viewed in the direction of revolution of said link matstructure.

7. A circulating device for loose materials as defined in claim 4,wherein said link elements are constructed to define substantiallyrakelike members and are positioned rearwardly at an inclination towardsthat side where there is desired :1 transverse feed of the loosematerial to be circulated as viewed in the direction of revolution ofthe link mat structure.

8. A circulating device for loose materials as defined in claim 1,wherein said link mat structure includes a deflecting region at itslower end, and weighting means disposed at the inside surface of saiddeflecting region.

9. A circulating device for loose materials as defined in claim 8,wherein said weighting means comprises a freely supported roller body.

10. A circulating device for loose materials, especially for aerobicdecomposing organic wastematerials, comprising a movable undercarriagemovable in a predetermined direction of travel and located above theloose material to be acted upon, scraper conveyor means arranged at saidundercarriage, said scraper conveyor means comprising a conveyor bandequipped with entrainment means, said conveyor band extending into theloose material in the form of a substantially triangular conveyor bandstructure which tapers downwardly, said conveyor band being formed as alink conveyor composed of heavy links, and means mounting said linkconveyor to be freely suspended beneath said undercarriage.

11. The circulating device as defined in claim 10, wherein said linkconveyor is formed of a plurality of individual, adjacently arranged,link chains defined by said heavy links and which are hingedly connectedwith another, and means for connecting together with play neighboringlink elements which extend substantially transversely with respect tothe direction of travel of said neighboring link chains of said linkconveyor.

12. The circulating device as defined in claim 11, further including aseparate support frame for at least each of said link chains, saidsupport frames being individually and independently adjustable relativeto one another with respect to said undercarriage.

13. The circulating device as defined in claim 11, further including aseparate support frame foreach given group of link chains, said supportframes being individually and independently adjustable relative to oneanother with respect to said undercarriage.

14. The circulating device as defined in claim 11, wherein said chainlinks are constructed as substantially rakelike elements and, viewed inthe direction of travel of the link conveyor, are rearwardly inclined toboth sides of their center line.

15. The circulating device as defined in claim 14, wherein said chainlinks are constructed as substantially rakelike elements and, viewed inthe direction of travel of the link conveyor, are rearwardly inclinedtowards that side where there is intended to be imparted a substantiallytransverse conveying motion to the circulating loose material.

16. The circulating device as defined in claim 10, wherein saidentrainment means comprises prong members inclined opposite to thedirection of travel of said link conveyor.

17. The circulating device as defined in claim 10, wherein said linkconveyor includes a deflecting region. at its lower end, and weightingmeans disposed at the inside surface of said deflecting region.

18. The circulating device as defined in claim 17, .wherein saidweighting means comprises a freely supported roller body.

19. The circulating device as defined in claim 10, further includingdrive means for revolving said link conveyor in the direction of travelof said undercarriage and further including brake means for controllingsaid speed of travel of said undercarriage.

20. The circulating device as defined in claim 19, further including asupporting surface for said brake means, said brake means comprises afriction wheel mounted to travel upon said supporting surface, and meansoperatively connecting said friction wheel with said drive means.

21. The circulating device as defined in claim 20, wherein saidoperatively connecting means incorporates a drive roller with which saidfriction wheel is connected.

1. A circulating device for loose materials, especially foraerobic-decomposing organic waste materials, comprising an undercarriagemovable in a predetermined direction of advance, two upper deflectingdevices mounted in spaced relationship at said movable undercarriage, afreely suspended, revolving, endless heavy link mat structure guidedover said two upper deflecting devices, means for driving at least oneof said deflecting devices, entrainment means for the loose materialprovided at the outside surface of said link mat structure, saidentrainment means being distributed over said surface of said link matstructure, the direction of revolving of said endless link mat occurringfrom its top towards the bottom at the side situated in the direction ofadvance of the circulation device, said link mat structure beingcomposed of individual adjacently arranged endless chains formed of linkelements, and coupling means for hingedly connecting together said linkelements of neighboring chains.
 2. A circulating device for loosematerials as defined in claim 1, wherein said coupling means couplestogether neighboring link elements with play.
 3. A circulating device asdefined in claim 2, wherein said two upper deflecting devices comprisesindividual deflecting elements for each revolving chain moving through arespective associated revolving plane which are adjustably mounted sothat it is possible to regulate independently of one another the saidrevolving planes of the individual chains.
 4. A circulating device forloose materials as defined in claim 1, wherein said entrainment meanscomprise prong members arranged at said individual link elements.
 5. Acirculating device for loose materials as defined in claim 4, whereinsaid prong members are inclined opposite to the direction of revolvingof said link mat structure.
 6. A circulating device as defined in claim4, wherein said link elements are constructed to possess theconfiguration of substantially rakelike members which from theircenterline are inclined rearwardly to both sides viewed in the directionof revolution of said link mat structure.
 7. A circulating device forloose materials as defined in claim 4, wherein said link elements areconstructed to define substantially rakelike members and are positionedrearwardly at an inclination towards that side where there is desired atransverse feed of the loose material to be circulated as viewed in thedirection of revolution of the link mat structure.
 8. A circulatingdevice for loose materials as defined in claim 1, wherein said link matstructure includes a deflecting region at its lower end, and weightingmeans disposed at the inside surface of said deflecting region.
 9. Acirculating device for loose materials as defined in claim 8, whereinsaid weighting means comprises a freely supported roller body.
 10. Acirculating device for loose materials, especially for aerobicdecomposing organic waste materials, comprising a movable undercarriagemovable in a predetermined direction of travel and located above theloose material to be acted upon, scraper conveyor means arranged at saidundercarriage, said scraper conveyor means comprising a conveyor bandequipped with entrainment means, said conveyor band extending into theloose material in the form of a substantially triangular conveyor bandstructure which tapers downwardly, said conveyor band being formed as alink conveyor composed of heavy links, and means mounting said linkconveyor to be freely suspended beneath said undercarriage.
 11. Thecirculating device as defined in claim 10, wherein said link conveyor isformed of a plurality of individual, adjacently arranged, link chainsdefined by said heavy links and which are hingedly connected withanother, and means for connecting together with play neighboring linkelements which extend substantially transversely with respect to thedirection of travel of said neighboring link chains of said linkconveyor.
 12. The circulating device as defined in claim 11, furtherincluding a separate support frame for at least each of said linkchains, said support frames being individually and independentlyadjustable relative to one another with respect to said undercarriage.13. The circulating device as defined in claim 11, further including aseparate support frame for each given group of link chains, said supportframes being individually and independently adjustable relative to oneanother with respect to said undercarriage.
 14. The circulating deviceas defined in claim 11, wherein said chain links are constructed assubstantially rakelike elements and, viewed in the direction of travelof the link conveyor, are rearwardly inclined to both sides of theircenter line.
 15. The circulating device as defined in claim 14, whereinsaid chain links are constructed as substantially rakelike elements and,viewed in the direction of travel of the link conveyor, are rearwardlyinclined towards that side where there is intended to be imparted asubstantially transverse conveying motion to the circulating loosematerial.
 16. The circulating device as defined in claim 10, whereinsaid entrainment means comprises prong members inclined opposite to thedirection of travel of said link conveyor.
 17. The circulating device asdefined in claim 10, wherein said link conveyor includes a deflectingregion at its lower end, and weighting means disposed at the insidesurface of said deflecting region.
 18. The circulating device as definedin claim 17, wherein said weighting means comprises a freely supportedroller body.
 19. The circulating device as defined in claim 10, furtherincluding drive means for revolving said link conveyor in the directionof travel of said undercarriage and further including brake means forcontrolling said speed of travel of said undercarriage.
 20. Thecirculating device as defined in claim 19, further including asupporting surface for said brake means, said brake means comprises afriction wheel mounted to travel upon said supporting surface, and meansoperatively connecting said friction wheel with said drive means. 21.The circulating device as defined in claim 20, wherein said operativelyconnecting means incorporates a drive roller with which said frictionwheel is connected.